1. The Digestive System (simplified!)

2. Learning Goals
I will be able to explain how food is digested and nutrients absorbed into the body

3. Let’s learn how our body digests food.
Digest means to break down food in the body.

4. Esophagus
When you chew your food, it mixes with a liquid in your mouth called saliva.
Saliva helps break down food.
Once food has been chewed and swallowed, it goes down a tube called the esophagus.

5. Stomach
Once the food goes down the esophagus, the food enters the stomach.
The stomach continues to break down the food. It has muscles that mash food into a sloppy soup.

6. Large and Small Intestines
Food leaves the stomach and enters the small intestine. Nutrients your body needs from the food you eat goes to all parts of the body.
You have about 20 feet of small intestines.
Food that your body does not need goes to the large intestine. L S

7. Digestive System
Digestion begins when food enters the mouth where saliva and teeth break it down.
Once food has been chewed and swallowed, it goes down a tube called the esophagus to the stomach.
Stomach muscles mix the food and moves it to the small intestine.
Food that your body does not need goes to the large intestine.

8. Using Nutrients
Once food has been broken down into nutrients, digestion is complete
You body still has work to do though
It must absorb the nutrients and take them to where they can be used or stored

9. Absorption Nutrients are absorbed into the bloodstream
Most absorption takes place in your small intestine

10. Processing and Storing Nutrients
After absorption, nutrients are carried through a blood vessel called the portal vein to the liver
One of the livers jobs is to turn nutrients into forms the body can use
Example:
Converts amino acids into different kinds of proteins
The proteins are then carried by the blood to where they are needed

11. Processing and Storing Nutrients
If not needed immediately nutrients are stored
Example:
Extra glucose is converted by the liver into glycogen
Stored in the liver and in muscles
If there is more than can be stored it is converted to body fat
Fats are then deposited throughout the body as and energy reserve

12. Processing and Storing Nutrients
Minerals are stored in various ways
Some examples:
Iron is stored in the liver and bone marrow
Fat-soluble vitamins are stored mainly in the liver and body fat

13. READ A Letter To the Digestive System (It’s a PDF)

14. It’s not just the digestive system though!!!
Nutrients affect the whole body including (but not limited to):
Nervous system
Circulatory system
Immune system
Endocrine system (hormones)
Your turn!
The Task: A Letter of Complaint similar in style to the Digestive System Letter. Don’t forget your citations!!!!